Author: Boone, David Alan
Title: Investigation of socket reactions from transtibial prosthesis malalignment
Degree: Ph.D.
Year: 2005
Subject: Hong Kong Polytechnic University -- Dissertations.
Prosthesis.
Orthopedic implants.
Orthopedic apparatus.
Department: Department of Health Technology and Informatics
Pages: xviii, 272 leaves : ill. (some col.) ; 30 cm.
Language: English
Abstract: The effects of transtibial prosthesis malalignment on transtibial prosthetic socket reactions were measured in terms of axial force, sagittal moment and coronal moment. In addition, complementary study of amputee perceptions of their alignment and balance was undertaken. Mathematical predictive models of prosthetic alignment were created. Alignment perturbations of angulation and translation were induced from the baseline of a nominally "aligned" prosthesis as established by an experienced prosthetist. The Prosthesis Alignment Instrument, (PAI) was used to measure and affect sagittal and coronal changes in angular (+-3o and +-6o) and translational (+-5mm and +-10mm) alignment. An integral force transducer measured axial force, sagittal moment and coronal moment socket reactions. A wireless data acquisition system transmitted 100Hz PAI socket reaction data from consecutive steps, typically 15 meters at a time. Seventeen randomized alignment conditions were recorded with each of 11 subjects for a total of 187 trials. Trial identifiers, time, total axial force, sagittal socket reaction moment and coronal socket reaction moment were recorded to computer files at a sampling rate of 100Hz. Analysis by repeated measures ANOVA showed that socket malalignment had very significant effect on socket reactions in both the sagittal and coronal planes (p<0.000l, two-sided) with a maximum coefficient of determination (r2) of 0.9261. Subject perceptions were analyzed for Sensitivity and Specificity with regard to alignment perturbation and at least one of the Visual Analog scales was associated significantly with each malalignment (Fisher's Exact Test, p<0.05, two-sided). Discrete non-linear algebraic modeling of alignment was possible with prediction (r2) ranging from 0.8998 for coronal translations, and 0.9179 for coronal angulations to 0.8446 for sagittal angulation and 0.8498 for sagittal translations. Mean absolute prediction errors of models derived equated to only 1.13o of angulation and 1.96 mm of translation. With improved understanding of socket reactions as they relate to alignment it is hoped that future work will be able to establish objective criteria for optimal transtibial prosthesis alignment.
Rights: All rights reserved
Access: open access

Files in This Item:
File Description SizeFormat 
b18354130.pdfFor All Users12.96 MBAdobe PDFView/Open


Copyright Undertaking

As a bona fide Library user, I declare that:

  1. I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
  2. I will use the Database for the purpose of my research or private study only and not for circulation or further reproduction or any other purpose.
  3. I agree to indemnify and hold the University harmless from and against any loss, damage, cost, liability or expenses arising from copyright infringement or unauthorized usage.

By downloading any item(s) listed above, you acknowledge that you have read and understood the copyright undertaking as stated above, and agree to be bound by all of its terms.

Show full item record

Please use this identifier to cite or link to this item: https://theses.lib.polyu.edu.hk/handle/200/2216